Einstein, Newton and Darwin are the Galactic Warrior Rats, mutant hybrids who come under your control in this top-down multi-directional shooter. Their plan is to save the badly polluted planet Smeaton Five by destroying its robotic defences and the computer primed to explode it.

Many enemies must be shot down along the way, but most release credits when shot – wait a few seconds for these to appear. You have three lives, with each rat representing a life, which means that all upgrades are lost when you lose a life, and each rat’s protective biosphere has the ability to withstand a few shots. Before heading into the action, you can spend your initial 500 credits on upgrades and weaponry. Your movement features a degree of inertia, making it harder to stop short of a position.